Have you ever used a wireless keyboard? They're awful in that application, usually. They end up receiving 95% of keystrokes from where you want to sit, and you get more frustrated as the night wears on. Maybe the newly proposed Wireless USB spec will fix all that, though.

To quote this very site..from the FAQ
WILL THERE BE A WIRELESS VERSION? WILL THERE BE A SMARTPHONE, POCKET PC OR OTHER VERSION FOR BATTERY-POWERED DEVICES?

No. Given the current consumption of the LED backlighting, battery powered backlit keyboards are not practical. But the look of the LED backlighting speaks for itself; it would not be possible with other means of backlighting.